<!doctype html> 
<html> 
<head> 
    <meta charset="utf-8"> 
    <title></title> 
</head>
<script type="text/javascript">
	//var a = 10;
	alert(a);
</script>
<script type="text/javascript">
	var a = 10;
/*
	var a = 10;
	
	function b(){
		//var a;
		alert(a);
		var a = 30;
	}
	b();
*/
</script>
<script type="text/javascript">
	//a();
</script>
<body>

<div id='sad' class='asda' lll='1'></div>
</body>
</html>